The present disclosure relates to an image forming apparatus and particularly to a technique for allowing a user to recognize the current power mode.
Conventionally, there is known an image forming apparatus having a plurality of power modes with different power consumption. For instance, there is already known a multifunction peripheral having a power save mode in which power consumption is reduced. In addition, in this multifunction peripheral, even if there is a factor indicating a certain warning, the multifunction peripheral becomes the power save mode when a request to switch to the power save mode is issued, and a display unit displays a message indicating there is a warning.
Further, in recent years, in a so-called sleep mode in which power consumption is reduced like the power save mode described above, it is required to reduce power consumption as much as possible. Accordingly, there is also known an image forming apparatus having a plurality of sleep modes with different degrees of saving power consumption. In this image forming apparatus, the power mode is appropriately switched to one of the sleep modes in accordance with a use situation of the apparatus, so that power consumption is reduced as much as possible in accordance with the use situation of the apparatus.
The above-mentioned image forming apparatus having a plurality of sleep modes controls a display unit to display information indicating a current power mode even if the power mode is the sleep mode, in order that a user can recognize the current power mode. However, this image forming apparatus has a problem that it is impossible to stop voltage supply to an operation unit equipped with a display control unit such as an ASIC for controlling the display unit and information display on the display unit when the power mode is the sleep mode.
In order to solve this problem, there is known a method in which a light emitting element such as an LED is provided to the operation unit, and further a control line is disposed between a main body control unit that integrally controls the entire apparatus and the operation unit. In this image forming apparatus, when the power mode is the sleep mode, voltage supply to the operation unit is stopped, and a voltage is supplied only to the main body control unit. Then, the main body control unit controls on/off state of the light emitting element via the control line. Thus, when the power mode is the sleep mode, voltage supply to the display unit and the display control unit is stopped. However, in this image forming apparatus, because it is necessary to dispose the control line between the main body control unit and the operation unit, a structure of the image forming apparatus may be complicated.